The invention refers to a container having a device for the electric measurement of the level of a liquid contained within it, which device comprises a strip-shaped conductive foil adapted to be washed by the liquid on both of its surfaces, for instance an externally electrically heated resistance foil, or a capacitance foil formed of at least two conductors.
A device for measuring the level of a liquid, intended for an automobile gasoline tank, is already described in senior German Patent Application No. P 32 35 534.3. This known device is inserted into the tank from the top so that there are no problems of sealing openings in the container. The device must be long enough that it extends as far as possible to the bottom of the tank since in measurement of the level the precision of the measurement with a low level of liquid is generally more important than with a high level of liquid. Unfortunately, the distance from the top of the tank to the bottom of the tank varies considerably since the manufacturing tolerances of such tanks are large and the bottom of the tank bulges downward due to the weight of the fuel.
In order nevertheless to obtain a sufficiently high precision of measurement even in the region of lower liquid levels elastic foil holders have been developed which rest resiliently against the bottom of the tank. It is also known to hold rigid foil holders continuously against the bottom of the tank by a spring. Such constructions are, however, rather expensive and are seldom used due to considerations of cost.
It is an object of the invention to develop a container having a device for the electric measurment of the level of the liquid contained in it by which a very accurate measurement of the level of the liquid contained in it is possible without the measuring device having to be made complicated for this purpose but with great freedom with regard to the configuration of the container.